The 1974 U.S. Open was referred to by sportswriter Dick Schapp as “The Massacre at Winged Foot” because the winner shot a seven over par, which is exceptionally high for a major championship.

Some of the top players missed the cut and complained that the course was too difficult. Members of the media accused the USGA of trying to embarrass the best golfers in the world.

“We’re not trying to embarrass the best golfers in the world," said USGA executive committee member Sandy Tatum, who was responsible for the setup of the course. "We are trying to identify the best golfers in the world.”

The same thing happened this weekend. The rough was high and the greens were hard and fast at Chambers Bay. It separated the best from the rest very quickly.

Tatum considered the conditions of that course the ultimate test for the best in the world. It’s the same in business -- market conditions are the ultimate test in identifying the best entrepreneurs.

There’s a universal truth to golf, amateur or professional, and regardless of a course’s difficulty, golfers will complain about the course conditions, stating that whatever is “wrong with it” just doesn’t suit their game.

Entrepreneurs will complain about their markets or the economy in a similar vein. But it’s not supposed to perfectly “suit your game.” You’re supposed to adjust your game to the market conditions. Just like the best golfers in the world adjust their game to the course conditions.

Whether it's course conditions in golf or market conditions in business, you will be tested. The lesson for entrepreneurs from the U.S. Open is that the best player doesn’t always win -- the one who plays the best does.

In both 1974 and this year’s U.S. Open, many of the world’s greatest golfers either didn’t make the cut or choked under pressure. Complaining is the ultimate saboteur. It hijacks your focus and steals your patience. The golfer who played the best in 1974 was Hale Irwin. In the 2015 U.S. Open it was Jordan Spieth. Both U.S. Open winners attributed their success to patience.

Sports psychologist Dr. Rob Bell explains that adversity helps the patient golfer. The mistake a lot of golfers make is that they feel they’re competing against the course and each other. The best golfers realize they are just competing against themselves.

It’s the same in business: You’re not competing against the market or the competition. You are competing against yourself. When you focus on conditions or the competition you divert your focus to things you can’t control.

A golfer can’t control how fast the greens are or how his opponent plays any more than an entrepreneur can control the stock market or his competition’s business model.

Focusing on the conditions is counterproductive. There are plenty of things we can complain about, but it's a waste of emotional energy to focus on things we cannot control. The ultimate test for us as entrepreneurs is to focus on the controllables.

All you can control is what I call your A.P.E. -- attitude, process and effort. These are the only three things we each have complete control over.

Perhaps the greatest example of focusing on what you can control is Jason Day. While he didn’t win the tournament, Day certainly knew he was competing against himself, not the course or his opponents. Day collapsed in the second round, suffering from vertigo. He managed to get back up and not only finish the round, but the tournament. Day birdied the final two holes and was even tied for the lead heading into the final round. He understood the greatest challenge wasn’t the course or the competition.

It’s a great lesson and great inspiration for us as entrepreneurs. It’s not about what’s happening around us or what’s happening to us, it’s about what’s happening inside us. Our biggest challenge is not the conditions or the competition, it’s ourselves.